These are the strangest animals in the world. One of them is immortal!

This strange sea creature is a cowfish and can be identified by the long horns that rise from the front part of the head like those of a cow or a bull. These fish range in length from 10 to 51 cm (4-20 inches) and live in the Indo-Pacific.

Photo: Osric de Guzman / Pixabay

The butterfly in the picture is a Glasswing. It got its name because of its transparent wings. Only the wing veins and the edges of the wings are scaled. It is mainly native to the tropics, but can also live in other ecosystems.

The fried egg (Cotylorhiza tuberculata) that swims in the Mediterranean Sea grows up to 35 cm (14 inch) in size. The venom of this jellyfish is not harmful to humans.

The blobfish isn't exactly handsome. That's why some people call him 'The ugliest animal in the world.' But he certainly doesn't care. His appearance is reminiscent of a grumpy, bald man and he is made of a slimy jelly.

Image: 'All Things Marine,' YouTube

This medusa, called Turritopsis nutricula, is immortal. It measures 4-5 millimeters (diameter) and undergoes reverse metaplasia, allowing it to revert to its polyp stage when feeling ill or threatened. This makes them the first known species with this ability.

Image source: YouTube

This sea creature has a long, shark -like body. One of the characteristics that distinguishes the sawfish from other rays is its long, serrated snout. There are small, saw-like teeth on each side.

The pink handfish (Brachiopsilus dianthus ) had been missing for 22 years and experts feared that it was extinct. However, he's still there, walking on the seabed. He was last sighted by a diver off the Tasmanian coast, according to the German magazine Der Spiegel.

Photo: Inedito / YouTube

This new species of snail was only discovered in 2010. She throws "love darts" made of calcium carbonate and hormones at her partner, hence the name "ninja" snail. Scientists believe this cupid-like behavior may increase their reproductive success.

Photo: CarlosAl1786 / YouTube

The striped tenrec (Hemicentetes) is a mammal and lives in Madagascar. You could say it's a hedgehog dressed like a bee.

Photo: Ben G. Thomas / YouTube

The almost smiling animal is a dugong. It is the smallest living manatee, the only representative of its genus, and the only surviving member of the Dugongidae family.

Glass frogs are native to South and Central America. Most of these have a light green back coloration and some members of this family have transparent abdominal skin. The internal organs such as the heart, liver, stomach and intestines are visible through the skin.

Photo: Canvapro

It's almost unbelievable, but this primate was only discovered by a team of scientists in 2010. Supposedly, the snub-nosed monkey only sits on rainy days and has its head between its legs, because otherwise the rainwater gets into its nose. However, should this happen anyway, the animal sneezes continuously to get the water out of its nose.

Photo: Oschu100 / YouTube

Perhaps the Ogcocephalidae has its red mouth to distract from the fact that it is a poor swimmer... or perhaps it serves to attract females? Marine biologists are not sure. Most of the time the sea bat moves with its fins over subtropical and tropical seabeds.

Glaucus atlanticus is a filamentous snail. It lives on the sea surface and eats cnidarians such as jellyfish. By eating poisonous animals, it becomes poisonous itself. This strange animals grows 3 to 5 cm (1-2 inches) long. It is native to warm Australian, European and African waters.

Photo:  Caramelo Talk / YouTube

The saiga (tatarica) has a trunk-like nose. It populates the Eurasian steppes. Unfortunately, the saiga is an endangered species as the horns are a popular ingredient in traditional Chinese medicine.

Photo: Oskanov / Canva

These tube-nosed flying foxes are just one of nearly 200 species found during two scientific expeditions to Papua New Guinea in 2009. Like other flying foxes, it disperses the seeds of the fruit it eats as part of its diet.

Is that a worm or a squid? Or maybe both?
Yes! Because this sea creature is called "squid worm" (Teuthidodrilus samae ).
According to researchers at the Woods Hole Oceanographic Institution and the Scripps Institution in California, this is a very important discovery because no other specimen with similar characteristics is known. In fact, the squid worm is currently the only animal in its genus.

Image source: YouTube

Since The Masked Singer 2021, the axolotl has become known to a wider public. Legend has it that the Mexican salamander is the Aztec god of fire and lightning, Xolotl, who disguised himself as a salamander to avoid being sacrificed.

Aye-ayes are unique to the island of Madagascar. These strange animals may not look like primates at first glance, but they are related to chimpanzees, monkeys, and humans.

The cute platypus is native to Australia and lives part in water and part on land. The strange thing about the mammal is that it lays eggs!

Native to Australia, this small sea dragon (up to 35 cm / 14' long) uses its long leaf-shaped appendages for camouflage. It is a marine fish related to the seahorse.

With this fish you can look directly into its (usually) transparent head. But don't worry, the toothless ghost fish lives far away in the dark of the deep sea.

Photo: 'Dein Universum' / YouTube

Dumbo octopuses are considered the deepest living octopus species. They live on the ocean floor or hover just above it at depths of 3000 to 4000 meters (2-2.5 miles). The ear-like fins protruding from the upper part of the Dumbo octopus' mantle resemble the ears of the Disney character Dumbo the flying elephant. And that's why he got the name Dumbo.

Photo: National Geographic / YouTube